As mosquito season descends upon the Midwest and fears over mosquito-borne illnesses continue to dominate headlines, a professor at Creighton University is hoping to prevent pesky bites and allay fears of disease with research he’s done toward finding the most effective mosquito repellent.

Philip J. Gregory, Pharm.D., an associate professor of pharmacy practice in the Center for Drug Information and Evidence-Based Practice in Creighton’s School of Pharmacy and Health Professions says EPA-registered mosquito repellents are the safest and most effective means for preventing mosquito bites in adults and children two months of age and older.

Such repellents include the ingredient DEET, found in such brand name products as OFF! Deep Woods Insect Repellent and Repel 100 Insect Repellent. Repellents with a 30 percent DEET concentration typically provide protection for six hours. Repellents with 20 to 23.8 percent DEET concentration protect for between four and five hours and repellents with 6.65 to 10 percent DEET concentration provide about one to three hours of protection.

Controlled-release products might offer a longer duration of protection, even with a lower DEET concentration.

Gregory said repellents with DEET concentrations over 50 percent offer no additional benefit or extended rate of protection.

“An important caveat in understanding the effectiveness of mosquito repellents is that higher concentration products are not necessarily more effective,” Gregory said. “However, higher concentrations typically result in a longer duration of protection. Manufacturers often estimate the protection time provided, but these estimates may not be supported by reliable evidence.”

Another active ingredient found in some repellents is picaridin, found in Avon’s Skin-So-Soft Bug Guard Plus Picaridin. A 20 percent picaridin concentration provides protection for up to seven hours and a 10 percent concentration offers protection up to five hours. Canadian regulators recommend against the use of picaridin for children under the age of six months.

IR3535, found in Avon’s Skin-So-Soft Bug Guard Plus IR3535, is usually found in a 7.5 percent concentration which gives about 10 minutes to one hour of protection and is safe for children aged two months or older.

Finally, lemon eucalyptus oil-based repellents usually provide protection for up to three hours, but are not recommended for children younger than 3.

Gregory said many natural mosquito repellents in the form of citronella oil, cedar oil, geranium oil and lemongrass oil, are on the market but not registered by the EPA. While many people think of these natural approaches as a safer alternative, the natural repellents are not as effective as those with an EPA registration mark and their level of safety may not be known.